Reeta Dhar has asked: Mr Gates, affordability of medicine is one of the key issues facing many of the poorest people in societies across both, the developing and the developed worlds. One of the catalysts is the long term patents issued to pharmaceutical companies, that at the end of the day, operate for profit. As an astute businessman, an innovator and a philanthropist, do you believe that such mechanisms are critical to drive innovation in the field of medicine or are these simply market distorting mechanisms that help create monopolies. If patents are indeed necessary or indispensable, what needs to change in the system to make medicine accessible to those who need it the most?